We are on the 2011 Student Freedom Riders bus rolling toward Augusta, Ga., watching “The Murder of Emmett Till,” a PBS documentary on the savage 1955 lynching of a black boy in the nothing town of Money, Miss. On the old newsreel footage, white person after white person spews the grotesque bigotry that was common to white people in that time and place, and somebody asks Ryan Price a question:

How do you feel as a white guy, watching a film like this?

“It was a good question,” he tells me that evening at the hotel. He pauses a long time, thinking.

“Watching ‘The Murder of Emmett Till’ as a white person,” he says, “it’s hard not to …”

Another pause. He gathers himself. “It’s hard not to be embarrassed,” he says finally. “While I was watching that movie, you get to the point where you almost want to change your skin color so you can show how much you care about issues of race, how much you care about the overt hatred and vitriolic discrimination of the past and today. Of course, you can’t change your skin color, but you can be an ally to those who are marginalized in society, and that’s something it really spurs me to do.”

It is a good — and brave — answer. Sadly, such bravery often eludes people two and three times the age of Price, a 20-year-old student from Drake University in Des Moines, Iowa. Their preferred answer, proffered reflexively whenever discussion turns to the African-American sojourn in this country, can be summed up in three words: don’t look back.

As the bus full of college students rolls across the South celebrating the young people who famously defied segregation ordinances 50 years ago, and promoting “Freedom Riders,” a new PBS documentary, that preferred answer is being heard yet again. Indeed, a story on the freedom rides by your humble correspondent, who is traveling across the South with the student riders, drew the following odd, but entirely predictable, rebuke on a Miami Herald message board.

“Cars’ windshields are so large and the rearview mirrors are so small because our past is not as important as our future. So, look ahead and move on.”

One never encounters this wholesale dismissal of the past when one commemorates, say, the Kennedy inauguration or the Holocaust. That’s because those things makes us feel sorrow, nostalgia, resolve. As Ryan Price would testify, African-American history makes us feel … other things.

And if we find those things difficult to process, that’s understandable. But to respond to that difficulty by declaring this one strain of history off limits is to commit an act of plain moral cowardice.

That cowardice is unfortunately common. Ray Arsenault, who wrote “Freedom Riders,” the book upon which the PBS documentary is based, says that instead of doing the difficult work of seeking to understand the forces that made us, Americans too often choose to create “mythic conceptions of what they think happened” in the past. Those myths, he says, are “based on half-truths and a kind of civic indoctrination which makes them feel perhaps more comfortable, but that trains them to be followers and not leaders, not to ask the difficult questions.” Without posing those questions, he says, we will never find the answers.

Which is, I suppose, just fine by some of us because it is those answers we fear. I mean, “windshields”? Really?

The funny thing is, every car I’ve ever driven had one in the back nearly as big as the one in the front — along with three mirrors reflecting the road behind. It suggests that automakers, at least, recognize what some of us do not.

To navigate the road ahead, it helps to have some sense of the road behind.

Leonard Pitts Jr. is a columnist for The Miami Herald. His e-mail address is: lpitts@miamiherald.com. Leonard Pitts will be chatting with readers every Wednesday from 1 p.m. to 2 p.m. EDT on www.MiamiHerald.com.